The NeuRx RA/4 Diaphragm Pacing Stimulation (DPS) System has been implanted in over 25 individuals with high-level spinal cord injury, resulting in over 20 years of cumulative active implantation time. The longest term patient was implanted March 6, 2000 and has been using the DPS System as his sole means of respiratory support for over five years. With the exception of the second patient, who does not meet our revised inclusion criteria and has gained no benefit from the implant, all of the remaining patients have been able to achieve significant tidal volumes with the DPS System. Based on the current results, the NeuRx RA/4 DPS System has demonstrated safety and efficacy in patients with high-level spinal cord injury.